A power supply, or pre-conditioner circuit, is a device for the conversion of electrical power having one set of characteristics into electrical power having another set of characteristics, to meet specified requirements.
Often, power supplies, or pre-conditioner circuits, must be used with three-phase utility networks. Such networks provide a typical supply voltage of approximately 400 V between phases, and considering all possible voltage variations, the rectified voltage supplied to the input of a pre-conditioner circuit (sometimes referred to as a line conditioner) may range between 400 and 750 VDC. As a result, the power components of the subsequent application should be designed to withstand the maximum voltage in this range. The purpose of a pre-conditioner is thus to generate a modified output voltage, for use driving a load of a main application. However, even though the components of the main application may be de-rated to reflect the lower voltage subsequent to the pre-conditioner, the components of the pre-conditioner itself must still be designed to operate at three-phase voltages.
WO 2006/051450 discusses a pre-conditioner topology which enables the components of the pre-conditioner to be de-rated. Such systems can be further improved, however.
US 2009/0066311 A1 discloses a pre-conditioner circuit comprising first and second preconditioner modules, each having an input and an output, the outputs being coupled to respective load modules.
U.S. Pat. No. 5,847,949 A discloses a boost converter for converting an input voltage received at an input thereof into first and second output voltages provided at first and second outputs thereof, respectively, a method of power conversion and a power converter employing the boost converter or the method.
JP 2002233151 A discloses a switching power circuit wherein one-side ends of a first snubber capacitor and a second snubber capacitor are connected to a junction between a first primary coil and a first switching means, and to a junction between a second primary coil and a second switching means, respectively.